Abstract A simple and accurate analytical model for defining the lateral strength of the multi-span RC frame with masonry infill has been developed in this study. This model is developed due to the limitation of the current analytical model which only can be applied to the single-span RC frame. Meanwhile, the structure in the building also is in a multi-span frame and masonry infill greatly impacts the portal structure. In the existing building, this analytical method is needed to calculate the lateral strength of the RC frame. Besides, the analytical method was developed based on the lateral strength analysis method of a single-span RC frame in which the modeling of a multi-span RC frame with masonry infill along with uniform span spacing was applied. Furthermore, an equivalent diagonal strut with the same thickness and material as the masonry panels was used instead of masonry infill in the frame structure. The external column has diagonal compressive forces on the top or bottom of the column. On the other hand, diagonal compressive forces work at the top and the bottom of the column in the internal column. The lateral strength of the infill was determined based on the frame infill contact length. Furthermore, in order to obtain the lateral strength of the structure, the experimental study of a multi-span RC frame with masonry infill under cyclic load was also tested. Applying the analytical model has shown promising results even after being compared with the results of the experimental work.
{"title":"Analytical Study on Lateral Strength of Multi-Span RC Frame with Masonry Infill","authors":"F. Nugroho, Maidiawati, J. Tanjung, Zaidir","doi":"10.2478/cee-2022-0042","DOIUrl":"https://doi.org/10.2478/cee-2022-0042","url":null,"abstract":"Abstract A simple and accurate analytical model for defining the lateral strength of the multi-span RC frame with masonry infill has been developed in this study. This model is developed due to the limitation of the current analytical model which only can be applied to the single-span RC frame. Meanwhile, the structure in the building also is in a multi-span frame and masonry infill greatly impacts the portal structure. In the existing building, this analytical method is needed to calculate the lateral strength of the RC frame. Besides, the analytical method was developed based on the lateral strength analysis method of a single-span RC frame in which the modeling of a multi-span RC frame with masonry infill along with uniform span spacing was applied. Furthermore, an equivalent diagonal strut with the same thickness and material as the masonry panels was used instead of masonry infill in the frame structure. The external column has diagonal compressive forces on the top or bottom of the column. On the other hand, diagonal compressive forces work at the top and the bottom of the column in the internal column. The lateral strength of the infill was determined based on the frame infill contact length. Furthermore, in order to obtain the lateral strength of the structure, the experimental study of a multi-span RC frame with masonry infill under cyclic load was also tested. Applying the analytical model has shown promising results even after being compared with the results of the experimental work.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43184736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This article studies the probabilistic analysis at the ultimate limit state (ULS) of a strip footing resting on a purely cohesive soil composed of two layers with spatial variability of the upper or lower layer and treats the simultaneous effect of the variability of the two layers on the probability of failure Pf value using the subset simulation approach. The results are examined by comparing the Pf values obtained with the Pf value corresponding to the reference case of two homogenous clay layers. In general, the subset simulation approach is used in cases of uncertain parameters modeled by random variables. But in this paper, it is employed with uncertain parameters modeled by random fields because the spatial variability of soil properties strongly affects the behavior of geotechnical structures and causes a significant change in the variability of their responses. The soil cohesion parameter is modelled as a non-Gaussian (log-normal) anisotropic random field using a square exponential autocorrelation function by the optimal linear expansion estimation (EOLE) and the deterministic model is based on numerical simulations using the finite difference software FLAC3D.
{"title":"Probabilistic Analysis of Strip Footings Using the Subset Simulation Approach and the Influence of Spatial Variability of Two Clay Layers","authors":"Jawad K. Thajeel, Amell Jabbar Thahab","doi":"10.2478/cee-2022-0064","DOIUrl":"https://doi.org/10.2478/cee-2022-0064","url":null,"abstract":"Abstract This article studies the probabilistic analysis at the ultimate limit state (ULS) of a strip footing resting on a purely cohesive soil composed of two layers with spatial variability of the upper or lower layer and treats the simultaneous effect of the variability of the two layers on the probability of failure Pf value using the subset simulation approach. The results are examined by comparing the Pf values obtained with the Pf value corresponding to the reference case of two homogenous clay layers. In general, the subset simulation approach is used in cases of uncertain parameters modeled by random variables. But in this paper, it is employed with uncertain parameters modeled by random fields because the spatial variability of soil properties strongly affects the behavior of geotechnical structures and causes a significant change in the variability of their responses. The soil cohesion parameter is modelled as a non-Gaussian (log-normal) anisotropic random field using a square exponential autocorrelation function by the optimal linear expansion estimation (EOLE) and the deterministic model is based on numerical simulations using the finite difference software FLAC3D.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44904553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Climate change has received significant attention lately as it has adverse environmental impacts. Among them, rising water levels in the reservoirs are of key concern for infrastructures such as dams. Dam officials are compelled to reconsider dam safety with the increment in catastrophic floods and accelerated dam failure issues. Relatedly, there are numerous earthen dams in the US that may not be up to the current design standards as these dams are aging. They possess a higher risk of failure due to various factors such as defects in design geometry, geologic materials, and hydrologic deficiency due to extreme storms associated with changing climate. Hence, this study focuses on evaluating the impacts of climate change on earthen dams and spillways by conducting a post-failure analysis of the two cascading dams, Edenville Dam and Sanford Dam, located in Michigan, USA, that failed in series in May 2020. The study aims to accomplish three main objectives: 1) to identify the role of climate change on recent dam failures of Edenville and Sanford, 2) to perform a Windows Dam Analysis Modules (WinDAM) C simulation for the failure analysis of the two dams, and 3) to perform Hydrologic Engineering Center - River Analysis System (HEC-RAS) simulation for the failure analysis of both dams by observing downstream propagation of flood with the detailed evaluation of depth and velocity. The overall results show that extreme storms and flooding are associated with the increase in temperature and precipitation rates, impacting overall dam safety. Careful precautions should be undertaken before any of these catastrophic dam events occur. The analysis is useful for the dam agencies as they reconsider their guidelines and policies for future updates.
{"title":"Impacts of Climate Change on the Environment, Increase in Reservoir Levels, and Safety Threats to Earthen Dams: Post Failure Case Study of Two Cascading Dams in Michigan","authors":"S. Ghimire, Joseph W. Schulenberg","doi":"10.2478/cee-2022-0053","DOIUrl":"https://doi.org/10.2478/cee-2022-0053","url":null,"abstract":"Abstract Climate change has received significant attention lately as it has adverse environmental impacts. Among them, rising water levels in the reservoirs are of key concern for infrastructures such as dams. Dam officials are compelled to reconsider dam safety with the increment in catastrophic floods and accelerated dam failure issues. Relatedly, there are numerous earthen dams in the US that may not be up to the current design standards as these dams are aging. They possess a higher risk of failure due to various factors such as defects in design geometry, geologic materials, and hydrologic deficiency due to extreme storms associated with changing climate. Hence, this study focuses on evaluating the impacts of climate change on earthen dams and spillways by conducting a post-failure analysis of the two cascading dams, Edenville Dam and Sanford Dam, located in Michigan, USA, that failed in series in May 2020. The study aims to accomplish three main objectives: 1) to identify the role of climate change on recent dam failures of Edenville and Sanford, 2) to perform a Windows Dam Analysis Modules (WinDAM) C simulation for the failure analysis of the two dams, and 3) to perform Hydrologic Engineering Center - River Analysis System (HEC-RAS) simulation for the failure analysis of both dams by observing downstream propagation of flood with the detailed evaluation of depth and velocity. The overall results show that extreme storms and flooding are associated with the increase in temperature and precipitation rates, impacting overall dam safety. Careful precautions should be undertaken before any of these catastrophic dam events occur. The analysis is useful for the dam agencies as they reconsider their guidelines and policies for future updates.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45310116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Insufficient resilience of the natural environment is one of the many problems with the foundation of linear structures, and one of the ways to solve the foundation of a linear structure is the stabilization of soils. Fine-grained soils are problematic for traffic construction. The properties of clay soils change due to climatic conditions. They swell and become plastic in the presence of water, shrink in dry conditions, increase in volume, and freeze due to frost. Improving the properties of fine-grained soils with lime is a suitable solution to the problem in traffic construction. The purpose of soil improvement is to modify soil properties such as creating soil without cavities and gaps, increasing shear strength, reduce compressibility and permeability, the soil must be able to transfer the load without further settling (or unnatural compression). Soil improvement can be defined as an intervention in the natural geological environment or artificially built earth structures (embankments, notches), the purpose of which is to increase the resistance of the subsoil, achieve even settlement of the structure or object, accelerate consolidation, optimally build earth structures, etc. We can encounter the stabilization of the subsoil in all types of constructions, but most often in line constructions and water management construction. In our article, we focus on the effects of soil treatment with lime. The treated soil was F8 (CH) clay with high plasticity.
{"title":"Effect of Lime Filling on the Compactibility of Clay Soils","authors":"R. Bulko, S. Masarovicová","doi":"10.2478/cee-2022-0047","DOIUrl":"https://doi.org/10.2478/cee-2022-0047","url":null,"abstract":"Abstract Insufficient resilience of the natural environment is one of the many problems with the foundation of linear structures, and one of the ways to solve the foundation of a linear structure is the stabilization of soils. Fine-grained soils are problematic for traffic construction. The properties of clay soils change due to climatic conditions. They swell and become plastic in the presence of water, shrink in dry conditions, increase in volume, and freeze due to frost. Improving the properties of fine-grained soils with lime is a suitable solution to the problem in traffic construction. The purpose of soil improvement is to modify soil properties such as creating soil without cavities and gaps, increasing shear strength, reduce compressibility and permeability, the soil must be able to transfer the load without further settling (or unnatural compression). Soil improvement can be defined as an intervention in the natural geological environment or artificially built earth structures (embankments, notches), the purpose of which is to increase the resistance of the subsoil, achieve even settlement of the structure or object, accelerate consolidation, optimally build earth structures, etc. We can encounter the stabilization of the subsoil in all types of constructions, but most often in line constructions and water management construction. In our article, we focus on the effects of soil treatment with lime. The treated soil was F8 (CH) clay with high plasticity.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46252761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The main aim of the research is to assess the light intensity and its impact on the productivity of research participants in educational buildings. The research was carried out in 18 rooms in teaching buildings in Poland and involved over two hundred volunteers. The tests were carried out with the following climate parameters: air temperature ranged from 20 to 25.1 °C, relative humidity from 18.16 to 50.9 %, and the concentration of carbon dioxide from 509 to 1634 ppm. The light intensity in the tested rooms ranged from 17.3 to 1095.1 lux. The parameters of the room temperature, carbon dioxide concentration, relative humidity and light intensity were recorded using a microclimate meter. The study participants were asked to answer questions about overall well-being, lighting quality, and productivity in each room. The results show that the air temperature has an effect on the productivity of the participants with the most preferable range of about 22 – 24 °C. It was also observed that productivity increased with improved well – being of the respondents. The analysed research also made it possible to check whether the users were satisfied with the light intensity. 74 % of respondents assessed that with the prevailing lighting, their productivity is normal, and they also felt best in rooms where the light intensity was 200 - 400 lux.
{"title":"Indoor Environment, Lighting Conditions and Productivity in the Educational Buildings","authors":"N. Krawczyk, L. Dębska","doi":"10.2478/cee-2022-0055","DOIUrl":"https://doi.org/10.2478/cee-2022-0055","url":null,"abstract":"Abstract The main aim of the research is to assess the light intensity and its impact on the productivity of research participants in educational buildings. The research was carried out in 18 rooms in teaching buildings in Poland and involved over two hundred volunteers. The tests were carried out with the following climate parameters: air temperature ranged from 20 to 25.1 °C, relative humidity from 18.16 to 50.9 %, and the concentration of carbon dioxide from 509 to 1634 ppm. The light intensity in the tested rooms ranged from 17.3 to 1095.1 lux. The parameters of the room temperature, carbon dioxide concentration, relative humidity and light intensity were recorded using a microclimate meter. The study participants were asked to answer questions about overall well-being, lighting quality, and productivity in each room. The results show that the air temperature has an effect on the productivity of the participants with the most preferable range of about 22 – 24 °C. It was also observed that productivity increased with improved well – being of the respondents. The analysed research also made it possible to check whether the users were satisfied with the light intensity. 74 % of respondents assessed that with the prevailing lighting, their productivity is normal, and they also felt best in rooms where the light intensity was 200 - 400 lux.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46255703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The identification of risks in construction projects gives advance indications of the potential risks that may occur during project planning, construction or management. Therefore, identifying those risks and preparing the necessary plans to respond to them is a key detail for the success of the project from its failure. The projects implemented in the manner of a Build Operate Transfer (BOT) contract are accompanied by many risks due to the multiplicity of parties and the multiplicity of their responsibilities, as well as the size of those projects because they are usually associated with infrastructure projects. The aim of this research is to identify the most prominent risks in BOT contracts and the planned response against each risk. The adopted methodology is through conducting interviews and a closed questionnaire (included 77 out of 100 respondents), and the adoption of statistical analysis through the SPSS program and the scale of relative importance.The relative importance index technique was used to rank the risks according to their importance and discuss the reasons for their classification. The results showed a list of the most important risks that would be generated if the BOT contract was applied to transportation projects in Iraq, as well as the appropriate planned response to each risk based on historical information for previous BOT projects.
{"title":"Appropriate Risk Response Planning of Build Operate Transfer Contracts for the Transportation Projects in Iraq","authors":"Suhail F. Radi Al-Aga, A. M. Burhan","doi":"10.2478/cee-2022-0040","DOIUrl":"https://doi.org/10.2478/cee-2022-0040","url":null,"abstract":"Abstract The identification of risks in construction projects gives advance indications of the potential risks that may occur during project planning, construction or management. Therefore, identifying those risks and preparing the necessary plans to respond to them is a key detail for the success of the project from its failure. The projects implemented in the manner of a Build Operate Transfer (BOT) contract are accompanied by many risks due to the multiplicity of parties and the multiplicity of their responsibilities, as well as the size of those projects because they are usually associated with infrastructure projects. The aim of this research is to identify the most prominent risks in BOT contracts and the planned response against each risk. The adopted methodology is through conducting interviews and a closed questionnaire (included 77 out of 100 respondents), and the adoption of statistical analysis through the SPSS program and the scale of relative importance.The relative importance index technique was used to rank the risks according to their importance and discuss the reasons for their classification. The results showed a list of the most important risks that would be generated if the BOT contract was applied to transportation projects in Iraq, as well as the appropriate planned response to each risk based on historical information for previous BOT projects.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46356951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A parametric optimization problem of cross-sectional sizes for cold-formed steel lipped channel structural members subjected to axial compression has been considered by the paper. An optimization problem is formulated to define optimum cross-sectional sizes of cold-formed structural member taking into account post-buckling behavior and structural requirements when stripe width, profile thickness and profile type are constant and specified in advance. Maximization of the load-carrying capacity of the cold-formed structural member has been assumed as purpose function. As optimization results cold-formed steel lipped channels with optimum dimensions have been obtained. Steel lipped channels structural members with the optimum cross-sectional dimensions have higher load-carrying capacities at the same material consumption (stripe width) comparing with the ones proposed by the manufacturer when the material consumption.
{"title":"Cross-Section Size Optimization of Cold-Formed Steel Lipped Channel Structural Members Subjected to Axial Compression","authors":"V. Yurchenko, A. Perelmuter, I. Peleshko","doi":"10.2478/cee-2022-0044","DOIUrl":"https://doi.org/10.2478/cee-2022-0044","url":null,"abstract":"Abstract A parametric optimization problem of cross-sectional sizes for cold-formed steel lipped channel structural members subjected to axial compression has been considered by the paper. An optimization problem is formulated to define optimum cross-sectional sizes of cold-formed structural member taking into account post-buckling behavior and structural requirements when stripe width, profile thickness and profile type are constant and specified in advance. Maximization of the load-carrying capacity of the cold-formed structural member has been assumed as purpose function. As optimization results cold-formed steel lipped channels with optimum dimensions have been obtained. Steel lipped channels structural members with the optimum cross-sectional dimensions have higher load-carrying capacities at the same material consumption (stripe width) comparing with the ones proposed by the manufacturer when the material consumption.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48443256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The value of the total aerodynamic resistance of the structure is depended on the values of the highly variable coefficients of external pressure, the quantification of which is a typical task of aerodynamics of structures solved on a rigid model in a wind tunnel. The aim of the paper is to analyze the distribution of wind pressure on a 150 m high chimney of a nuclear power plant. Due to today’s changing climate and the emergence of unwanted windstorms, it is necessary to pay increased attention to tall and slender structures, where the effects of wind play an important role. The effect of wind, the influence of the terrain and surrounding structures has a significant impact on the safety of the chimney, which is a part of the nuclear power plant, where increased safety is required not only for the chimney itself but also for buildings in its immediate vicinity. Surrounding structures can modify wind flow and cause increased chimney load. Experimental measurements were performed in the STU BLWT wind tunnel in Bratislava, where the influence of the changing terrain, as well as the influence of the surrounding objects on the external wind pressure coefficients at different altitude levels were monitored.
{"title":"The Wind Tunnel Study of the Influence of Terrain and Surrounding Structures on the Distribution of Wind Pressure on a Chimney","authors":"O. Hubová, M. Franek, Ivana Véghová","doi":"10.2478/cee-2022-0048","DOIUrl":"https://doi.org/10.2478/cee-2022-0048","url":null,"abstract":"Abstract The value of the total aerodynamic resistance of the structure is depended on the values of the highly variable coefficients of external pressure, the quantification of which is a typical task of aerodynamics of structures solved on a rigid model in a wind tunnel. The aim of the paper is to analyze the distribution of wind pressure on a 150 m high chimney of a nuclear power plant. Due to today’s changing climate and the emergence of unwanted windstorms, it is necessary to pay increased attention to tall and slender structures, where the effects of wind play an important role. The effect of wind, the influence of the terrain and surrounding structures has a significant impact on the safety of the chimney, which is a part of the nuclear power plant, where increased safety is required not only for the chimney itself but also for buildings in its immediate vicinity. Surrounding structures can modify wind flow and cause increased chimney load. Experimental measurements were performed in the STU BLWT wind tunnel in Bratislava, where the influence of the changing terrain, as well as the influence of the surrounding objects on the external wind pressure coefficients at different altitude levels were monitored.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48512927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ezzat Gazy Al-Hamad, A. Ragab, Mohamed Mohsen Elattar, D. Sadek
Abstract The present work addresses conducting an experimental comparison between different types and dosages of fibers and nanomaterials in compressive tests and the cost of mixes for high-strength concrete (HSC). This study investigated the materials used in the construction sector in Egypt. The experimental work was carried out to select the optimum percentage of each type of the used nanomaterials, and fibers to achieve the highest compressive strength and low cost. In this work, nineteen concrete mixes were prepared. Nano silica (NS) and nano clay (NC) were used at 0, 1, 2, and 3 % by weight of cement. Also, nano- fumed silica (FS) was used at 0, 1, 2, 3, 5, and 10 %, while silica fume (SF) was used at 10 % by weight of cement. Each type of corrugated round steel fiber (STF), and polypropylene fibers (PPF) were used at 0.5, 0.75, and 1.00 % by concrete volume. The results indicated that the compressive strength of the HSC increases as the percentage of adding nano-fumed silica increases up to 3 % and the economic feasibility of nano-fumed silica in concrete is better than in other nanomaterials such as nano silica and nano clay. Also, using 1 % steel fiber in HSC increases concrete strength significantly compared to conventional concrete without considerably increasing the cost.
{"title":"Experimental Comparison of Fibers and Nanomaterials in Compression Test and Cost of High Strength Concrete in Egypt","authors":"Ezzat Gazy Al-Hamad, A. Ragab, Mohamed Mohsen Elattar, D. Sadek","doi":"10.2478/cee-2022-0068","DOIUrl":"https://doi.org/10.2478/cee-2022-0068","url":null,"abstract":"Abstract The present work addresses conducting an experimental comparison between different types and dosages of fibers and nanomaterials in compressive tests and the cost of mixes for high-strength concrete (HSC). This study investigated the materials used in the construction sector in Egypt. The experimental work was carried out to select the optimum percentage of each type of the used nanomaterials, and fibers to achieve the highest compressive strength and low cost. In this work, nineteen concrete mixes were prepared. Nano silica (NS) and nano clay (NC) were used at 0, 1, 2, and 3 % by weight of cement. Also, nano- fumed silica (FS) was used at 0, 1, 2, 3, 5, and 10 %, while silica fume (SF) was used at 10 % by weight of cement. Each type of corrugated round steel fiber (STF), and polypropylene fibers (PPF) were used at 0.5, 0.75, and 1.00 % by concrete volume. The results indicated that the compressive strength of the HSC increases as the percentage of adding nano-fumed silica increases up to 3 % and the economic feasibility of nano-fumed silica in concrete is better than in other nanomaterials such as nano silica and nano clay. Also, using 1 % steel fiber in HSC increases concrete strength significantly compared to conventional concrete without considerably increasing the cost.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44306076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This study performed the 2-dimensional modeling of Indonesia’s conventional track and the asphaltic underlayment track according to four different cyclic loading conditions by varying the train speeds and bogie load of Indonesia’s Argo Jati passenger trains set. Three different mechanical responses were considered, i.e., horizontal strains, vertical stress, and deformation, to investigate and compare the performance of Indonesia’s conventional track and the asphaltic underlayment track and to seek the possibility of Indonesia’s passenger trains to travel with higher speed and heavier axle load in the future. The numerical simulation results conclude that the asphaltic underlayment track capable of serving Argo Jati passenger trains set with the medium speed, 240 km/h, or 100 % higher than the existing operating speed. In addition, the application of a 20 cm asphalt layer below ballast will allow each passenger coach to carry the maximum payload up to 30 tons, or 50 % higher than the existing maximum payload. Furthermore, asphaltic underlayment track utilization in Indonesia’s railway systems could be beneficial for the optimization of the life cycle cost of the rail track since it could reduce the structure’s height, minimize the maintenance needs, and decrease track deterioration especially the mud pumping and deformation.
{"title":"Conventional and Asphaltic Underlayment Track Performance Subjected to Argo Jati Passenger Trains","authors":"D. Setiawan","doi":"10.2478/cee-2022-0036","DOIUrl":"https://doi.org/10.2478/cee-2022-0036","url":null,"abstract":"Abstract This study performed the 2-dimensional modeling of Indonesia’s conventional track and the asphaltic underlayment track according to four different cyclic loading conditions by varying the train speeds and bogie load of Indonesia’s Argo Jati passenger trains set. Three different mechanical responses were considered, i.e., horizontal strains, vertical stress, and deformation, to investigate and compare the performance of Indonesia’s conventional track and the asphaltic underlayment track and to seek the possibility of Indonesia’s passenger trains to travel with higher speed and heavier axle load in the future. The numerical simulation results conclude that the asphaltic underlayment track capable of serving Argo Jati passenger trains set with the medium speed, 240 km/h, or 100 % higher than the existing operating speed. In addition, the application of a 20 cm asphalt layer below ballast will allow each passenger coach to carry the maximum payload up to 30 tons, or 50 % higher than the existing maximum payload. Furthermore, asphaltic underlayment track utilization in Indonesia’s railway systems could be beneficial for the optimization of the life cycle cost of the rail track since it could reduce the structure’s height, minimize the maintenance needs, and decrease track deterioration especially the mud pumping and deformation.","PeriodicalId":42034,"journal":{"name":"Civil and Environmental Engineering","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2022-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49315090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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